Three substantive seminars for grapegrowers and their crews highlighted the Napa Valley Viticultural Fair Nov. 14, providing education on leafroll virus, the cost to growers of extended hang time and, en Español, an overview of grapevine pests and diseases. The fair also boasted colorful demonstrations of assistance dogs sniffing out vine mealybugs and new technologies for weed control.

The fair at the Napa Valley Expo grounds was sponsored by the Napa Valley Grapegrowers (NVG) and attended by 800 registrants, with 123 suppliers exhibiting their goods and services in the trade show indoors and 25 exhibiting outdoors. Eighteen nonprofits also exhibited. Registrants came not just from Napa, but from Sonoma, Lodi and other parts of the state. It was a chance for growers and their employees to bone up on technical issues, meet and greet suppliers, kick the tires on new equipment and compare notes with their comrades on the weird 2006 growing season, which had ended for many only two weeks prior.

An alarm about leafroll was sounded by Deborah Golino, director of foundation plant services at UC Davis, and Ed Weber, Napa County's viticulture farm advisor for the UC Cooperative Extension. Golino briefed an audience on the nine viruses that can turn vine leaves red or purple in late summer, which have made a noticeable comeback in some vineyards recently. Weber presented results of a study on a Cabernet Sauvignon vineyard that was newly overcome by leafroll this decade. (Please see page 50 for more details.)

Next, Weber revealed findings from a two-year study on extended hang-time, which sought to quantify the relationship between extra ripening time and loss of tonnage. His results gave growers a new magic number to help them in negotiating with their winery customers who want ultra-ripe fruit--5% weight loss per degree Brix above 26.

Equipment displays including these pruners were multi-color and multi-manufacturer.

Arnufo Solario of Silverado Farming Company led the seminar in Spanish designed to give vineyard workers an overview of the many grapevine pests and diseases commonly seen in North Coast vineyards. Since fieldworkers spend more time in the vineyards than anyone else, increasing their knowledge can have a big impact on improved vineyard management.

Most entertaining was a demonstration by the Assistance Dog Institute of Santa Rosa, Calif., of its dogs' prowess in detecting vine mealybugs in vineyards by smell alone. The institute set up a mock vine row on the expo grounds, and placed in the row pieces of wood that were scented with a pheromone given off by female mealybugs. Josh, a golden retriever trained to respond to this scent since he was a very young puppy, walked down the row on command and readily stopped, pointed and barked at the correct spots.

Edwina Ryska said the institute starts training the pups at three weeks, with positive reinforcement to teach them to respond to the mealybug odor. "Our mission is helping dogs help people," she said, adding that the mealybug dogs are closely related to search-and-rescue dogs. Vine mealybugs are very difficult to spot visually in vineyards until they've already done damage, but the dogs are expected to be able to identify single infected vines among many acres and make it possible to control the pests by treating or removing only those vines.

Ryska said she expects at least four dogs will be available by spring 2007 to get to work in real vineyard situations. No fee schedule had yet been determined. Several wine industry individuals and groups, including NVG, have contributed to the Vine Mealybug Detection Project, which is now in its second year. For more information or to make a donation, visit assistance-dog.com or phone (707) 545-DOGS.

The NVG has decided to turn the biennial event into an annual one. The 2007 fair will be Wednesday, Nov. 14, at the Napa Valley Expo.